Are you using the z-bar to actuate the clutch release arm? Hard to tell from the picture. Why not mount the slave horizontally and hook it directly to the clutch release arm and eliminate the z-bar entirely? Like I say, I can't really tell from the picture which way you've gone with your design. Fewer parts, especially removing a part like the z-bar are one of the main advantages to hydraulic clutches.
Your set-up would have to be changed a bit, but it would be much more mechanically efficient with it mounted horizontally and directly to the throw-out arm. Just be sure to keep the bleeder pointed up and at the highest point on the install. I've seen most home-brewed installs done this way.
Also, I know you mentioned you are aware of this, but you MUST run the spring to pull the throwout bearing back away from the clutch fingers or it will wear out in no time. As soon as the grease warms in the throwout bearing, it will quickly migrate out onto your clutch friction. There are no really seals in it to speak of, so when it get s hot, the grease is the first thing to go, the bearing itself.
Same thing happens for guys who like to drive with their foot resting on the clutch pedal and/or rest their hand on the shifter. That causes unnecessary wear too. The only tie a clutch and transmission really get wear is when they are being used. try to limit the amount of time you unnecessarily hold in the clutch, slip it on take off and don't use it as a hill holding device while waiting for the car in front of you to move and it will last a lot longer. And keep you hand off the shifter when you drive unless you can do it without pushing it slightly towards one gear or another.
Auto shop 101 in 1978, from Mr Arenson @ Fremont High School Sunnyvale, CA....RIP. Good man!
